Technical Specifications

Write ADRs, RFCs, and design documents

Introduction

Write technical specifications, Architecture Decision Records (ADRs), Request for Comments (RFCs), and design documents that drive better technical decisions. Use structured templates, version history, and AI assistance to create clear, comprehensive technical documentation.

Good technical specs are the foundation of successful engineering projects. They capture context, document decisions, and provide a reference for future work.

Why AutEng for Technical Specs?

Structured Templates

Follow best practices with structured formats for ADRs, RFCs, and design docs. AI helps you fill in the sections and ensures you don't miss important details.

Decision Tracking

Version history tracks every decision and change. See why decisions were made and how they evolved over time. Never lose context again.

Easy Review Process

Share specs with stakeholders using public links. Visual diffs make it easy to see what changed between versions during review cycles.

Architecture Decision Records (ADRs)

ADRs document important architectural decisions, their context, and consequences. They help teams understand why decisions were made and provide a historical record.

ADR Template Example

ADR 001: Use PostgreSQL for Primary Database

Status

Accepted

Context

We need to choose a database for our new application. Requirements:

  • ACID compliance for financial transactions
  • Support for complex queries and joins
  • Strong ecosystem and community support
  • Ability to scale vertically and horizontally

Decision

We will use PostgreSQL as our primary database.

Consequences

Positive

  • Excellent ACID compliance and data integrity
  • Rich feature set (JSON, full-text search, etc.)
  • Strong community and tooling support
  • Good performance for our use case

Negative

  • Requires more operational expertise than managed NoSQL
  • Vertical scaling has limits
  • Need to plan for replication and backups

Alternatives Considered

  • MySQL: Similar features but weaker JSON support
  • MongoDB: Better horizontal scaling but no ACID guarantees
  • DynamoDB: Fully managed but vendor lock-in concerns

Request for Comments (RFCs)

RFCs propose changes and gather feedback from your team. They're perfect for planning major features, architectural changes, or process improvements.

RFC Template Example

RFC: Implement Rate Limiting for Public API

Summary

Implement rate limiting on our public API to prevent abuse and ensure fair usage.

Motivation

We've seen increased API usage that's impacting performance for all users. We need to:

  • Prevent abuse and DoS attacks
  • Ensure fair resource allocation
  • Protect backend services from overload

Proposed Solution

Implement token bucket rate limiting at the API gateway level:

Rendering diagram...

Rate Limits

TierRequests/minuteBurst
Free6010
Pro600100
EnterpriseCustomCustom

Implementation Plan

  1. Phase 1: Add rate limiting middleware (Week 1)
  2. Phase 2: Implement Redis-backed storage (Week 2)
  3. Phase 3: Add monitoring and alerts (Week 3)
  4. Phase 4: Roll out to production with logging only (Week 4)
  5. Phase 5: Enable enforcement (Week 5)

Alternatives Considered

  • Application-level limiting: More complex, harder to maintain
  • Third-party service: Additional cost and latency

Design Documents

Design documents detail system designs before implementation. They help teams align on approach and identify issues early.

Design Doc Example

Design: Real-time Notification System

Goals

  • Deliver notifications to users in real-time
  • Support multiple channels (web, mobile, email)
  • Handle 10,000+ concurrent connections
  • Ensure message delivery (at-least-once)

Architecture

Rendering diagram...

Components

Message Queue

  • Use Redis Streams for message buffering
  • Supports consumer groups for scaling
  • Persistence for reliability

WebSocket Server

  • Node.js with Socket.io
  • Horizontal scaling with Redis adapter
  • Automatic reconnection handling

Notification Workers

  • Python workers using Dramatiq
  • Process messages from queue
  • Route to appropriate channel

Data Model

interface Notification {
  id: string
  userId: string
  type: 'info' | 'warning' | 'error'
  title: string
  message: string
  channels: ('web' | 'mobile' | 'email')[]
  createdAt: Date
}

Security Considerations

  • Authenticate WebSocket connections with JWT
  • Rate limit notification creation
  • Validate user permissions before delivery

Best Practices

  • Start with context: Explain the problem and why it matters before jumping to solutions
  • Document alternatives: Show what options you considered and why you chose your approach
  • Use diagrams: Visual representations make complex systems easier to understand
  • Be specific: Include concrete examples, data models, and implementation details
  • Track decisions: Use version history to see how specs evolved during review
  • Keep it updated: Update specs as implementation reveals new information

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